The Guardian led with this story on Sunday:
"Tension between the US and Iran heightened dramatically today with the disclosure that Barack Obama is deploying a missile shield to protect American allies in the Gulf from attack by Tehran."
Many news elements are present in this lead, and at the same time, there are some unresolved questions.
Major questions like who, what, where and when are answered. The players are The US and her allies versus Iran. A missile shield shield is what has entered the conflict and the action is taking place in the Persian Gulf (though not explicitly named as such) today (Sunday).
The wording is overly general in this lead. A reader has to assume many things with this lead. Readers not familiar with geography, or a reader looking at this story later in the week, might have a different frame of reference than that which the writer uses.
Also, the word "disclosure" is too vague. The sentence is constructed to conveniently skirt around the fact that Barack Obama did not make a direct declaration of this missile shield. In fact, it isn't until the fifth paragraph that the writer of this article admits that this information comes from a leak by an unnamed senior administrator and that the announcement is not "formal."
This lead reflects timeliness, conflict, prominence (with Obama), and especially impact. But sensationalism seems to be the prevailing element.
Since The Guardian is a British news organization, it is possible that some of their customs in writing news are different than what we are learning in our American classroom. But this particular lead still leaves some things to be desired.